I have a very basic 5 year old Kenwood head unit, 8" kicker sub and 300 watt kicker amp, every since I installed pioneer 4-way 5x7s all around the speakers seem to cut out after a long duration of blasting music, the speakers aren't wired to the amp so does this mean that the head unit needs upgraded?

i have a standard cab, and did a 2way amp to the front 2 speakers. if you want to power all 4, i'd look for amp that delivers at least 50rms x4. sounds to me like you're over power the head unit. next time the music cuts out, feel the unit to see if it's hot.

It has the same RMS watts and peak power as the one you mentioned, so hopefully it'll work out good. It has a ipod hookup thru a auxilary output, how much different is the aux hookup than a usb hookup?

Most (Meaning 99% or better) head units dont have built in voltage amplifiers. Thus, maximum rail voltage is 12v. This means that into a 4ohm load you will never get more than 36w RMS...That is IF your unit is running at 100% efficency which it is not.

the aux input v. the usb, is the usb will constantly charge and usually usb has an interface on the head unit to browse your ipod...the aux is basically just making your head unit a set of headphones to the ipod

Most (Meaning 99% or better) head units dont have built in voltage amplifiers. Thus, maximum rail voltage is 12v. This means that into a 4ohm load you will never get more than 36w RMS...That is IF your unit is running at 100% efficency which it is not.

:-)

Alright, I'm not very audio inclined and it sounds like you know what your talking about, so knowing the system isn't 100% efficient are you saying that 22w rms is respectable out of a possible 36w rms? Or do you mean that under ideal conditions the unit would theorectially only put out 22w rms?... I'm just sort of confused by all this. I'm just trying to achieve a better than "stock" sound system, so spending the least amount of money is my limiting factor, at this point at least.

Alright, I'm not very audio inclined and it sounds like you know what your talking about, so knowing the system isn't 100% efficient are you saying that 22w rms is respectable out of a possible 36w rms? Or do you mean that under ideal conditions the unit would theorectially only put out 22w rms?... I'm just sort of confused by all this. I'm just trying to achieve a better than "stock" sound system, so spending the least amount of money is my limiting factor, at this point at least.

You've got it down. 22-25w RMS is the most I would ever trust comming out of a head unit. If they are claiming any more than that they are probably full of it.